Surface-gage



NlTED STATES PATENT OFFICE.

BURNSIDE E. SAWVYER, OF FITOHBURG, MASSACHUSETTS.

SURFACE-GAG E.

SPECIFICATION forming part of Letters Patent No. 624,876, dated May 9,1899.

Application filed December 22, 1898. serial No. 700,031. (No model.)

To aZZ whom it may concern:

Beit known that I, BURNSIDE E. SAWYER, a citizen of the United States,residing at Fitchburg, in the county of Worcesterand State ofMassachusetts, have made certain new and useful Improvements inSurface-Gages, of which the following is a specification.

It is the object of my invention to provide an improved surface-gage ofthat class in which a quick primary adjustment and a second and fineradjustment of the scriber may be effected. To this end I employ a basehaving a slot that permits the gage-bar, with its attached scriber, toswing through a Wide are, and I provide an improved meansto wit, arotatable eccentric-for effecting the fine adjustment of such gage-barand scriber.

The details of construction and operation are as hereinafter described,referring to the accompanying drawings, in which Figure 1 is aperspective view of my improved instrument. Fig. 2 is an enlargedvertical section of the same. Fig. 3 is an enlarged vertical section onthe line 3 3 of Fig. 2. Fig. 4 is a vertical section on the line 4 4 ofFig. 2. Fig. 5 includes perspective views of the parts composing theeccentric adj ustment for the gage-bar and scriber. Fig. 6 is ahorizontal section showing the base of the instrument in plan. tratingthe use of the instrument as a depthgage, &c.

The base A of the instrument is formed of two like side portions 1,which are joined by a web 2, and separated by a lengthwise slot in whichthe gage-bar B, with its attached and adjustable scriber O, is held andadapted to swing through an arc of about two hundred and twenty-fivedegrees. The said gage-bar and scriber are constructed in the usualmanner, and the scriber is adj ustably held on said bar by means of awell-known form of screwclamp 3.

The side portions 1 of the base A are beveled at one end on the innerside, as shown at 4, Fig. 1, to adapt it for application to cylindricaland other allied forms in a well-known manner. It is further providedwith vertical projections 5 on the upper side of each part or jaw 1, thesides of the same being parallel and at right angles to the upperhorizontal Fig. 7 is a View illusfaceot said base. The function of theseprojections 5 is illustrated in a general way in Fig. 7, it being topermit the instrument to be used as a depth-gage or as a substitute fora carpenters scriber. Thus in practical use the projections 5 andadjacent horizontal surface of the base abut and slide on the flat orplane surfaces that form the angular edge of the piece or work a: to betested. The gagebar B extends horizontally over the piece 00 and thescriber G is clamped thereon at a right angle, so as to reach the lowersurface of the piece as, as shown. It is obvious that the scriber C maybe adjusted higher to adapt it to work on a surface in the same planewith that on which the projections 5 rest and slide.

The gage bar 13 passes diametrically through a rotatable cylinder orshaft D, Fig.

2,wh ich serves as the primary means for holding and clampingthegage-bar in any desired position. For this purpose the cylinder isarranged transversely in the parts 1 of base A. The inner end of saidcylinder D is reduced and enters and seats on a coiled-wire spring 6,which is held loosely in a cavity 7 in one of the sides orjawsl of thebase. A thin washer 8, Fig. 2, is applied to the cylinder D at the outerend of the cavity 7.

The outer end of rotatable cylinder D is reduced and screw e threaded,and a milled clamping-nut E is applied to the same and seats on arotatable cylinder F. The latter has an exterior milled portion 9, (seeFig. 5,) a reduced portion 10, which is cylindrical exteriorly andeccentric interiorly, and an intermediate shoulder 11. The thimbleGcomprises a cylindrical body 12 and enlarged disk-like portion or end13, having a radial open slot 14. The body 12 of said thimble fits inthe eccentric bore of cylinder F, and the disk or head 13 abuts theinner endof the latter,-- as shown in Fig. 2. The notch 14 in disk 13receives or fits over a fixed stud 15,

(see Figs. 2 and 3,) so that the thimble G is.

prevented from rotating. When the parts are assembled as shown in Fig.2, the shoulder 11 of cylinder F abuts a shoulder of one of the parts orjaws 1 of base A, and its concentric body 10 fits rotatably in a bore ofthe same part, which bore is in alinement with the bore 7 in theopposite part or jaw 1.. The

spring 6 presses the rotatable cylinder D outward, so that the gage-barB is held or pressed forcibly against the thimble G.

It will be apparent that in gaging a piece of work the scriber C may bequickly adj usted to approximately the right position by loosening theclamp-nut E and the gage-bar clamp 3. For more accurate adjustment ofthe scriber the cylinder F is rotated more or less, whereby itsinteriorly-eccentrio portion 10 will obviously move the thimble G up ordown correspondingly. In Fig. 2 the thicker portion of part 10 is at thelower side of cylinder G, and consequently the gage-bar B and itsscriber C are adjusted as high as the rotation of cylinder F can effect.If now the said cylinder. be rotated half-way around, the eccentric willbe shifted to move the scriber downward to the extent of the degree ofeocentricity of part 10. Within these limits there are several degreesof practicable adjustment. adjustment of the scriber may be effected,following the primary or coarse adjustment of the same.

It will be understood that the size of the cavity 7 permits suchshifting of the cylinder D as is incident and necessary to the describedadjustment of the gage bar and scriber through the medium of theeccentric.

What I claim is-' l. The combination with the base having a lengthwiseslot and transverse bores, of a rotatable cylinder having an eccentricbore, the rotatable cylinder D passing through said bores and traversingthe slot, the gage-bar having a scriber attachment and passingtransversely through the last-named cylinder, and a nut applied to thelatter for clamping the gage-barin any adjustment, substantially asshown and described.

2. The combination with the slotted and bored base, of the rotatablecylinder having an eccentric bore and seated in the base, the thimblehaving an enlarged head and fitted loosely in said bore, means forpreventing rotation of said thimble without hindering its verticalmovement, another cylinder journaled in the thimble a clamping-nutapplied Hence a very fine or accurate final to such cylinder and actingagainst the outer end of the eccentrically-bored cylinder, and thegage-bar arranged to swing in the slot of the base, as shown anddescribed.

3. The combination with the slotted base having alined transverse bores,asprin g seated in the smaller bore, the rotatable cylinder seated onsaid spring, a concentric thimble, a rotatable cylinder having aneccentric bore in which the thimble is seated, a clampingnut, and thegage-bar passing through the first-named cylinder and held in contactwith the inner end of the thimble, substantially as shown and described.

4. The combination of a gage-bar, having an attachment for holding ascriber, a slotted base in which said gage-bar swings, a thimble withshoulder at outer end, an eccentric cylinder inclosing said thimble, anda threaded rotatable cylinder arranged in a transverse bore of the basewith nut-lock for locking said gage-bar to the base, as shown and forthe purpose described.

5. The combination of a gage-bar with attachment for holding scriber, aslotted base having a projection at the top the vertical sides of whichare squared with the upper horizontal face of said base and alsoprovided with a transverse bore, a thimble with a shoulder at outer end,an eccentric cylinder inclosing said thimble and fitted rotatably insaid bore, a threaded rotatable cylinder with nut for locking saidgage-bar to base, practically as shown and for the purpose described.

6. The combination of a gage-bar with attachment for holding scriber, aslotted base in which the gage-bar is adapted to swing having a V-shapedopening at one end running vertically to the horizontal plane of thebase, a thimble with shoulder at outer end, an eccentric cylinderinclosing said thimble and arranged in a bore of the base, a threadedcylinder-D having a not for locking said gagebar to gage-base,practically as shown and for the purpose described.

BURNSIDE E. SAWYER.

Witnesses:

STEPHEN FRYE, ANDREW J. HAMILTON.

